The OnError event is used
to notify the application for errors occurring in backround processing and
during applications event handling. Such errors may happen, if the application
causes an exception within an event handling procedure or if a TAPI error
is catched during updating of TAPI data structures. If ThbTapiApplication.OnError
is assigned, this event is triggered before to enable a global error notification.
A ThbTapiLine instance as the sender annd in general the causer of the
event.
Causer
If the error has been caused by a sublimentary object like a call,
this object is presented as the causer. In general, this parameter is
nil and can be ignored.
Error
The exception that has been catched. You could write the exception's
message property to a log file or display it otherwise.